Just wanted to conduct a quick survey among fellow tsikoteers who does this kind of thing.

I'm using a Sipura SPA-3000 ATA device with Free world dialup for VOIP communications to the States.

Complemented by a Portech MV-370 VOIP-GSM interface that allows anyone with VOIP access anywhere in the world to call any cellular network in the Philippines for free. I use this especially with sun cellular in combination with their 24/7 Unlimited Call feature.